Abstract

CHERNICOFF, C.J.; SANTOS, J.O.S.; ZAPPETTINI, E.O.  and  MCNAUGHTON, N.J.. Early Paleozoic schists in the Green Quarry (35°04´S- 65°28´O), Southern San Luis: U-Pb SHRIMP ages and geodynamic implications. Rev. Asoc. Geol. Argent. [online]. 2007, vol.62, n.1, pp.154-158. ISSN 0004-4822.

At the Green quarry, southern San Luis province, there are scarse exposures of medium grained quartz-plagioclase-biotite schists of sedimentary origin. These outcrops are bounded to the east by a major N-S trending (Lonco Vaca) fault. U-Pb SHRIMP dating of 42 detrital zircons indicate that most grains are Neoproterozoic (n=20) and Cambrian (n=13). The age of the youngest detrital zircon is ca 500 Ma, which corresponds to the maximum age for the onset of sedimentation, indicating that deposition occurred during the Upper Cambrian- Ordovician. Equivalent and coeval metasediments are exposed in the sierra Lonco Vaca (La Pampa province). The metasediments of the San Luis Formation would also be equivalent and partly contemporaneous.

Keywords : Lower Paleozoic schists; Green quarry; San Luis; Argentina; U-Pb SHRIMP dating.

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